Rearranging Differential Equation

Hi, I was going over my notes and didnt understand one of the steps made in a calculation, was hoping someone could explain it to me.

Im trying to find an analytic solution for an ODE: dY/dX + X*Y = X

The integrating factor is I = e^((X^2)/2)

Multiplying the equation with the integrating factor

I*(dY/dX) + X*I*Y = X*I

This next step I dont follow where it gets simplified to:

(d/dX)*(Y*e^((X^2)/2)) = X*(e^((X^2)/2))

The following line's after are:

YI = I

Y = 1 + C*I

Any help would be appriciated, thank you.